Tension-adjuster for piano-keys.



No. 774,96 1. PATENI'ED NOV. 15, 1904.

0| 0| TENSION ADJUSTER FOR PIANO KEYS.

' APPLICATION FILED MAY 24, 190$- 2 SHEETS-SHEET 1.

N0 MODEL.

Charles award wuemtoz No. 774,961 PATENTED NOV. 15, 1904-.

- -c. c. WARD.

. TENSION ADJUSTER FOR PIANO KEYS. APPLICATION FILED MAYM, 1904. NO MODEL. 2 SHEETS-SHEET 2.

charles'uward, awe/ 50%, $4 0K J{ M aktozvwq.

1 i v m w/// 7/ UNITED STATES Patented November 15, 1904.

PATENT OFFICE.

TENSION-ADJUSTER FOR PIANO-KEYS.

SPECIFICATION forming part of Letters Patent N0. 774,961, dated November 15, 1904.

Application filed May 24, 1904. Serial No. 209,440. (No model.)

To all whom it may concern:

Beit known that I, CHARLES (lVVARD, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Improvement in Tension-Adjusters for Piano- Keys, of which thefollowing is a specification.

This invention relates to piano-actions, and particularly to means whereby the tensional resistance of the keys may be variedthat is to say, whereby the action may be stiffened or lightened at will; and the invention consists in certain novel combinations and arrangements of elements, substantially as hereinafter described, and particularly pointed out in the subjoined claims.

My invention is illustrated by the accompanying drawings, Figure 1 being an end view of my device mounted upon the key-bed of a piano. Fig. 2 is a front elevation of the same with the front board a removed and with the major portion of shaft g broken away. Fig. 3 is a relatively enlarged view of the ratchet-bark and its coacting bolt. Fig. 4 is a transverse sectional view taken on line 4: 4c of Fig. 2 looking in the direction of the arrow. In this view the hammer-action is indicated in dotted lines. In Fig. 5 I have shown a cross-section of rod 9 and of one of several wire stays which I provide to prevent the end portion of bar a from springing upward when said bar is rocked to corripress the springs Referring to the drawings, the letter a denotes the key-bed of a piano, (0 the front board, and b the ham mer-action. Mounted to slide vertically in a bar 0, extending from end to end of the piano, are rods 0, whose upper ends engage thehammer-actions and whose lower ends rest upon the inner ends of the piano-keys, said keys being indicated in the drawings by the reference-letter d. (See Figs. 1 and 4 of the drawings.) The bar 0 is so supported that it may be adjusted vertically within certain limits. As here shown, the said bar is slidably mounted on posts 6 e, located at the ends of the key-bed and fixed therein. Bar 0 is suspended on the free ends of arms j, that extend radially from a rocker bar 9, journaled in stands h it, secured to the keybed a. When the bar 9 is suitably rocked in its bearings, the bar 0 will be raised or lowered, according to the direction of rotation of said bar 9.

The lower ends of the rods 0 always maintain an established position that is to say, they always rest upon the inner ends of the keys d--and said rods are held thus in engagement with the keys by springs 2 whose upper ends abut the under side of bar 0 and whose lower ends abut flanged heads 0 fixed upon the lower end portion of the rods 0. When the bar 0 is lowered, it will be obvious that allof the springs will be compressed, and they will then bear with increased force upon the flanged heads 0 and when the springs are thus adjusted it will be obvious that the entire action will be stiffened and that greater force must be exerted in pressing down the keys d in the act of playing the instrument. It will be obvious that the rods 0 may be of solid wood or the like material, or tubes of light material, like aluminium, may be used, in which latter instance any slight difference in the flexibility of the springs c' could be easily counteracted by dropping one or more lead shot into those tubes 0' whose springs were found to be too weak.

I will now proceed to describe the means here shown for rocking the rod g and for retaining the same in any desired position to which it may have been adjusted.

Secured to one end of rod g is a depending arm g, to whose lower free end is pivotally connected a rod Zr, that extends tothe front of the piano and is slidably supported in a plate or escutcheon m, that is fixed to the front board a of the piano.

When the rod k is drawn outward, the arm g rocks the rod g and the arms f will lower the bar 0, and thus compress the springs c' and stifl en the action. On the other hand, if the rod in be pushed inward the rod 9 will be rocked in the opposite direction and the bar 0 will be raised, allowing the springs to expand, and thus lightening the action.

In order to lock the parts in the positions to which they have been adjusted, I have notched the rod in and have provided in the plate m a pin 71., whose lower end may engage the said notches, as seen in Figs. 1 and 3 of the drawings. It should be understood, however, that any other simple device could be utilized for retaining the rod it in its adjusted position and also that means other than that illustrated could be provided for raising and lowering the bar 0 without departing from the spirit and intent of my invention, the essential feature of said invention being in the spring-controlled interposed connections and means for adjusting the force exerted by said springs rather than in the particular means provided for accomplishing the said adjustment.

My described device adds very little to the cost of pianos, and it may be added to such instruments without expensive changes and without requiring rearrangement of the action or other operative parts of such instru ments.

Having thus described my invention, 1 claim 1. In combination with the keys of a piano, and the rods which connect said keys with the hammer-action; a bar mounted to slide on said rods, springs encircling said rods and interposed between said bar and the keys,and means for adjusting and supporting said bar, comprising a rocker-bar having radially-extending arms from which the first-mentioned bar is suspended and also having a depending arm, a rod connected to said arm and operated to adjust the same, and means connected with said rod for fixing the same in adjusted position.

2. In combination with the keys of a piano, and the rods which connect said keys with the hammer-action; posts mounted at the ends of the key-bed, a bar slidably mounted on said posts and through which said rods are free to move, springs engaging said bar and keys, and means for adjustably supporting said bar to thereby regulate the tension of said springs and permit the same to be varied simultaneously, comprising pivotally-mounted arms from which said bar is suspended, means for rocking said arms, and means for fixing the same in adjusted position.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

GHARLES C. WVARI).

Witnesses:

FRANK H. ALLEN, H. F. DAGGETT. 

